Composition for coating metal, plastic and wood substrates to impart wood-like appearance and texture thereto

ABSTRACT

Compositions are provided for forming a coating on metal, plastic or wood substrate wherein the coating has the appearance and texture of wood, conceals joints on the surface of the substrate and is capable of accepting conventional wood stain.

This is a continuation of application Ser. No. 07/824,693 filed Jan. 21,1992, now abandoned, which is a continuation of application Ser. No.07/274,756 filed Nov. 22, 1988, now abandoned.

The present invention is directed to a composition for coating metal,plastic or wood substrates to render them capable of receiving woodstains while also concealing joints and other imperfections in thesubstrate.

There are many applications in building construction in which theappearance of wood would be desired over metal, plastic or compositewood substrates. If wood itself is used as a substrate, a coating mightconceal joints and imperfections in the wood. For plastic and metalsubstrates, such as exposed surfaces on doors, window frames and thelike, it would be desirable to have the appearance and texture of wood.Moreover, to have a decorative effect, it would be desirable to be ableto stain a wood-like surface to a desired color, such as walnut,rosewood, and the like, and then to cover it, if desired, with aprotective coating, such as varnish, or other conventional clearcoating.

It is therefore an object of the present invention to providecompositions which are useful for coating metal, plastic or woodsubstrates to impart the appearance of a solid piece of natural woodwhich is capable of receiving conventional wood stains.

These and other objects will be apparent from the following descriptionand preferred embodiments.

The compositions of the present invention are basecoats for coveringmetal, plastic or wood substrates comprising a combination of resins,solvents, pigments, suspension agents, thickeners, wetting agents andabsorption agents. The composition will be applied as a liquid basecoatonto a metal, plastic or wood substrate and the volatile solvents willbe evaporated to form a uniform solid coating. If desired, inkcompositions may be applied to the coating in wood grain patterns beforestaining. The ink compositions may be those disclosed in commonlyassigned U.S. Pat. No. 4,546,133, the disclosure of which isincorporated herein by reference in its entirety.

Generally, the metal, plastic or wood substrate will first be coatedwith the liquid basecoat composition according to the present inventionand then dried to remove the volatile solvents. The drying is preferablyperformed with heat in a conventional oven, but other evaporativemethods may be utilized, particularly if a plastic surface is used asthe substrate, since excessive heat should be avoided in such a case toavoid warpage or other deformation. Then an ink formulation in a grainpattern may be applied to simulate a wood grain using a conventionalroller having a wood grain pattern. Apparatus for performing thesefunctions are conventional and known in the art.

The basecoat formulation according to the present invention has thefollowing components: alkyd resins, suspending agents, solvents, antimaragents, thickeners, melamine resins, wetting agents, pecan shell flour,white, yellow, black and red pigments and extenders, generally in thefollowing proportions:

    ______________________________________                                                       % Volume                                                       ______________________________________                                        Alkyd resins     3-4                                                          Maleic resins    3-4                                                          Xylene           14-18                                                        Other vol. solvents                                                                            2-3                                                          Anti-marring agent                                                                             2-4                                                          Tripentaerythritol                                                                             40-45                                                        Melamine resin    7-10                                                        Wetting agent    0.01-0.1                                                     Deodorant        0.2                                                          Thickener        5-8                                                          Pecan shell flour                                                                              0.1-0.3                                                      White pigment    5-6                                                          Yellow pigment   1.0                                                          Black pigment    trace                                                        Red pigment      trace                                                        Talc extender    4-6                                                                           100%                                                         ______________________________________                                    

    ______________________________________                                        The preferred basecoat composition contains                                   proportionally the following:                                                 Component    Amount        Function Mfg.                                      ______________________________________                                        Alkyd resin  5.6 gal       Resin    Pinjoic Mod.                              RJ-100       5.6 gal       Maleic resin                                                                           Monsanto                                  Xylene       23.5 gal      Solvent                                            Collidisperse                                                                              .09 gal       Wetting agent                                                                          Troy                                      Chlorowax    4.54 gal      Antimarring                                                                            ChemControl                                                          agent                                              Tripentaerythritol                                                                         64.25 gal     Absorption                                                                             Hercules                                                             agent                                              Superfine Melamine                                                                         12.7 gal      Melamine Melamine                                                             resin    Corp.                                     Solvent 150  3.56 gal      Solvent  Chemtech                                  Deodorant    0.3 gal                Guardsman                                 EHEC soln.   9.6 gal       Thickener                                                                              Hercules                                  Nytal 300    7.0 gal       Extender Vanderbilt                                Pecan shell flour                                                                          1.7 gal       Absorption                                                                    agent                                              Titanium dioxide                                                                           8.0 gal       Pigment                                            (white)                                                                       Yellow pigment                                                                             1.5 gal       Pigment                                            Black pigment                                                                              .05 gal       Pigment                                            Red pigment  .05 gal       Pigment                                            ______________________________________                                    

In the above formulation, the resins are alkyd resins, melamine resinsand maleic resins which include, but are not limited to, resinscontaining alkyd compounds formulated with a resin such as unsaturatedpolyesters and a diallyl phthalate cross-linking monomer, as well asmelamine-formaldehyde resins, polyester resins, extended polyesters,polystyrene, vinyl resins, polyamide resins, urea resins, acrylicresins, phenolic resins, coumarone-indene resins, urea-formaldehyderesins, epoxy resins, silicone resins, ionomer resins, acetal resins,polyethylene, polypropylene, hydrocarbon resins, rubber derivatives,polycarbonate resins, phenoxy resins, fluoroplastics, styrene-butadieneresins, polyurethane resins, furane resins, polysulfone resins, esters,gums, and the like. Natural resins may be used, which include shellac,rosin copal resins, damar resins, manila resins, and the like.

Absorption agents utilized are tripentaerythritol and pecan shell flour.The pecan shell flour is a key ingredient to achieving the wood-liketexture and appearance according to the present invention and typicallywill be ground to the size of about 42 to 45 microns average diameter.

An antimarring agent, such as Chlorowax™, will be utilized, as well as athickener.

In addition, small amounts of wetting agents and a deodorant areutilized, such as Collidisperse™ (a wetting agent) and a conventionaldeodorant.

The solvents utilized include xylene and a commercial solvent known asSolvent No. 150 (made by Ashland or Chemtech). Other volatile solventsmay be utilized, including toluene, MEK, acetone, cellulose acetate,methylisobutyl ketone, turpentine, pine oil, petroleum spirits, naphtha,mineral spirits, methyl and ethyl alcohol, toluol, benzol, xylol, ethylacetate, amyl acetate, and the like.

Extenders such as talc (Nytal 300), clay, silica, whiting, gypsum, micaand barytes may be utilized in the amounts given above.

Finally, combinations of pigments are utilized to provide for astainable wood appearance. The majority of the pigments will be a whitehiding pigment, such as titanium dioxide. Other white hiding pigmentsinclude white lead, zinc oxide, lithopone, zinc sulfide, and basic leadsulfate. Another important pigment is a yellow pigment and may includesuch conventional agents as hansa yellows, ferrite yellows, cadmiumlithopone, zinc chromate, ocher, or litharge. Then, if desired traceamounts of black and/or red pigments may be utilized, such as the redpigments red lead, iron oxide, cadmium reds and the black pigments suchas carbon black, lamp black, graphite or magnetite black.

The amount of the solvents and volatile esters utilized will be in anamount sufficient to dissolve and/or suspend the various components toform a uniform suspension. It is desirable that the solvents comprisesome polar solvents but primarily nonpolar solvents will be utilized,such as xylene, along with trace amounts of slightly polar solvents suchas ketones. Higher molecular weight solvents may be utilized, such aspetroleum distillates and esters, many of which are commerciallyavailable. It will be understood that various modifications inproportions and components may be utilized without departing from thescope of the present invention.

It will be appreciated that in addition to, or as substitutes for theabove pigments, the basecoat may contain various typical inorganic ororganic pigments useful for wood grain, such as those iron pigmentsranging in color from yellow through red, reddish brown, and brown toblack, similar to those found in natural wood.

After applying the basecoat to the metal, plastic or wood substrate, itis dried, for example, in a conventional oven to remove the volatilesolvents thereby forming a hardened basecoat. The wood substrates may beany wood product having a wood surface including wood strips, with orwithout joints, wood sheet, including plywood and wood grained paper, orany other product derived from wood or wood pulp, sawdust, and the like.Plastic utilized as substrates may be any kind of conventional plastic,such as polyethylene, polyvinylacetate, polycarbonate, or any kind ofdurable plastic utilized as a construction material. Metal substratesaccording to the present invention in most cases, should preferably beprimed to receive the basecoat according to the present invention.Exemplary primers for aluminum, steel, iron, and tin includeconventional primers, such as polyester primers (PPG) or acrylic primers(Guardsman). Optionally, a tie-coat over-primer may be placed over themetal primer, such as a vinyl acrylic primer (Guardsman #447-0144). Anink formulation may then be applied to the dried basecoat with a rollerhaving a wood grain pattern. The ink formulation may comprise resins,pigments, absorption pigments, tinting agents and wetting agents, aswell as solvents. For example, those ink formulations disclosed incommonly assigned U.S. Pat. No. 4,546,133 and in copending commonlyassigned Ser. No. 103,440, filed Sep. 30, 1987 in the name of CarrollCope entitled PROCESS FOR COATING METAL AND PLASTIC IMPARTING WOOD-LIKEAPPEARANCES, the disclosure of which is incorporated herein byreference, may be utilized.

The pigments in the ink formulation should, of course, impart a color tothe basecoat which is different from the color of the dried basecoat, inorder to provide contrast. Usually, such colorants should impart yellowor brown tones.

The basecoat, after application of the ink formulation, if desired, willbe stained with a conventional wood stain which usually enhances thecontrast between the basecoat and the ink.

After application of the graining formulation, air drying and staining,the final product may be coated with a conventional varnish or otherclear preservative.

Having described the specific embodiments of the invention,modifications and variations will be apparent to those who are skilledin the art, which variations and modifications are intended to be withinthe scope of the present invention.

I claim:
 1. A liquid composition comprising:

    ______________________________________                                                            % Volume                                                  ______________________________________                                        Alkyd resins          3-4                                                     Maleic resins         3-4                                                     Xylene                14-18                                                   Volatile solvents other than xylene                                                                 2-3                                                     Anti-marring agent    2-4                                                     Tripentaerythritol    40-45                                                   Melamine resin         7-10                                                   Wetting agent         0.01-0.1                                                Deodorant             0.2                                                     Thickener             5-8                                                     Pecan shell flour     0.1-0.3                                                 White pigment         5-6                                                     Yellow pigment        1.0                                                     Black and red pigments                                                                              up to 13.69                                             Talc extender         4-6                                                                           100%                                                    ______________________________________                                    


2. A liquid composition according to claim 1 proportionally comprisingby volume:

    ______________________________________                                        5.6 parts       alkyd resin                                                   5.6 parts       maleic resins                                                 23.5 parts      xylene                                                        0.09 parts      wetting agent                                                 4.54 parts      antimarring agent                                             64.25 parts     tripentaerythritol                                            12.7 parts      melamine resin                                                3.56 parts      additional volatile solvent                                   0.3 parts       deodorant                                                     9.6 parts       thickener                                                     7.0 parts       talc extender                                                 1.7 parts       pecan shell flour                                             8.0 parts       titanium dioxide                                              1.5 parts       yellow pigment                                                0.05 parts      black pigment                                                 0.05 parts      red pigment                                                   ______________________________________                                    